Assault rifles typically include one or more (usually two) hand guard shells that at least partially surround a barrel to provide a comfortable grip and/or to provide protection from heat during firing. In such hand guard systems, supports or holding units at both a base end and a muzzle end of the barrel removably couple the hand guard shells to the firearm. The removable hand guard shells make it possible, for example, in the case of gas-operated firearms, to route or install a throttle control rod or a gas line that is coupled to a gas bleed port adjacent the muzzle end of the barrel into a housing or receiver adjacent the base end of the barrel. Such hand guard arrangements are typically employed, for example, in the M16 family of firearms.
Modern firearm systems increasingly demand additional component carriers (e.g., scopes, sights, etc.) to be mounted to the firearm above suitable coupling profiles such as, for example, a coupling profile of a Picatinny rail. In particular, for sighting or aiming components, it is often necessary to couple a component carrier to the barrel region of the firearm, if at all possible, without supporting the carrier on the barrel. In these instances, the holding units are typically removed and the component carriers are mounted to the firearm. In typical hand guard systems, however, the barrel must be removed in order to remove the holding unit, thereby limiting the flexibility of the rifle.
Thus, conventional hand guard systems often times limit the flexibility of a firearm because the use of a component carrier (e.g., a Picatinny rail, etc.) is only possible if the barrel is disassembled and the hand guard system, including the holding units, are replaced by the component carrier. This is particularly disadvantageous for firearms in which a sighting device is coupled to the barrel because removal of the barrel may require readjustment and/or recalibration of the sighting device. Additionally and/or alternatively, removal and reattachment of a barrel may be expensive and may require professional installation expertise.